Officer Aptitude Rating (OAR) Practice Test

To determine how long it will take the faster train to catch the slower train, we start by calculating the head start that the slower train has due to starting an hour earlier. In that one hour, the slower train, traveling at 40 mph, would cover a distance of 40 miles. Now, we need to find the time it takes for the faster train, which travels at 45 mph, to close the 40-mile gap between them. The relative speed between the two trains is the difference in their speeds, which is 45 mph (faster train) - 40 mph (slower train) = 5 mph. To find out how long it will take for the faster train to catch up, we divide the distance it needs to cover (40 miles) by the relative speed (5 mph). So the calculation is as follows: Time = Distance / Speed Time = 40 miles / 5 mph = 8 hours. Thus, it will take the faster train 8 hours to catch the slower train.